
PCG spots Chinese research ship, dozens of militia vessels near Rozul Reef
MANILA, Philippines – The Philippine Coast Guard (PCG) on Thursday said it has detected a Chinese oceanographic research vessel and more than 40 accompanying maritime militia‑type ships operating inside the country’s exclusive economic zone in the West Philippine Sea. [1][4][7]
What the PCG observed
During a maritime domain awareness (MDA) flight on Wednesday, a PCG Islander 4177 aircraft identified the Chinese research vessel Xiang Yang Hong 33 about 7.34 nautical miles west of Rozul Reef (Iroquois Reef), the agency reported. [4][7] The plane also saw the vessel deploying a small service boat toward the reef area, indicating active survey or scientific operations. [1][4]
Using data from Canada’s Dark Vessel Detection Program, the PCG said the Xiang Yang Hong 33 has been tracked moving across multiple features in the West Philippine Sea since April 15, when it departed Chinese waters. [1][6][9] These include Ayungin Shoal, Escoda Shoal, Panganiban Reef, and Rozul Reef, all within the Philippines’ 200‑nautical‑mile EEZ. [1][4][7]
“Gross disrespect” of UNCLOS, Manila says
The PCG stressed that marine scientific research within an EEZ can only be conducted with the consent of the coastal state, under the United Nations Convention on the Law of the Sea (UNCLOS). [3][6][9] Since Manila has not authorized such work by the Chinese vessel, the agency described the operation as “unauthorized” and “illegal.” [3][7][9]
“The presence of the research vessel and the large‑scale swarming by Chinese Maritime Militia vessels represent a serious infringement on Philippine sovereign rights and maritime jurisdiction; and gross disrespect to UNCLOS in which they are a party,” the PCG stated. [4][7][8]
Coast Guard Commandant Adm. Ronnie Gil Gavan said the agency would continue stepped‑up patrols and MDA flights “in line with international law.” [4][8] He added that the PCG would continue to challenge any activities it deems unlawful and aimed at undermining Philippine sovereignty. [4][7][9]
The PCG has increasingly relied on satellite‑based dark‑vessel detection and intelligence sharing, including with Canada, to document and publicize Chinese maritime activity around the Kalayaan Island Group and other features in the West Philippine Sea. [5][6][8] Officials say the clustering of dozens of Chinese vessels, including both research and militia ships, raises concerns about seafloor mapping, resource exploration, and operational control in contested waters. [1][4][7]
Notes:
[1] 40 Chinese ships seen in Philippines waters https://www.philstar.com/headlines/2026/05/08/2526426/40-chinese-ships-seen-philippines-waters-pcg [2] [PDF] Untitled - WEST PHILIPPINE SEA TRANSPARENCY GROUP https://wpstransparency.ph/wp-content/uploads/2026/05/2025-Semi-Annual-Report_final.pdf [3] PCG challenges Chinese research vessel surveying West ... https://mb.com.ph/2025/08/03/pcg-challenges-chinese-research-vessel-surveying-west-ph-sea-for-22-days-already [4] Over 40 Chinese vessels swarming around Kalayaan Island Group, PCG says https://www.gmanetwork.com/news/topstories/nation/986761/over-40-chinese-vessels-swarming-around-kalayaan-island-group-pcg-says/story/?amp [5] Assessment of the Philippines' Maritime Domain Awareness ... https://www.scspi.org/en/dtfx/assessment-philippines%E2%80%99-maritime-domain-awareness-capabilities [6] Philippines calls out China for deploying advanced research ships ... https://www.tribuneindia.com/news/world/philippines-calls-out-china-for-deploying-advanced-research-ships-in-philippines-exclusive-economic-zone/ [7] Philippines says China vessel conducting 'illegal' research near gas ... https://www.bworldonline.com/the-nation/2026/05/07/748122/philippines-says-china-vessel-conducting-illegal-research-near-gas-rich-reed-bank/ [8] PCG heightens patrol in WPS, makes public maritime incidents https://www.pna.gov.ph/articles/1196051 [9] PCG mobilizes assets to drive away 4 Chinese research vessels ... https://mb.com.ph/2026/05/03/pcg-mobilizes-assets-to-drive-away-4-chinese-research-vessels-operating-in-ph-waters [10] Over 40 Chinese vessels swarming around Kalayaan Island Group ... https://www.gmanetwork.com/news/topstories/nation/986761/over-40-chinese-vessels-swarming-around-kalayaan-island-group-pcg-says/story/